Deposits of the Udokan-Chineysky ore-magmatic system of Eastern Siberia

The aggregate of ore deposits localized in the Udokan-Chineysky ore district is unique and is the result of multi–stage, polygenetic formation. The deposits of copper and other metals formed at various depths occur within a limited area. The oxide and sulfide ore are spatially associated in the sedimentary rocks pertaining to the Paleoproterozoic Udokan Supergroup and the intrusive mafic–ultramafic rocks of the Chineysky Complex. The granite rocks of the Kodar Complex and gabbro rocks of the Chineysky Complex also date back to Paleoproterozoic. The same age has been established for metasomatic Nb–Ta–Zr–REE–Y and U mineralization in the albitized terrigenous rocks of the Udokan Supergroup (Katugin deposit and Chitkanda prospect) and U–Pd prospects hosted in terrigenous rocks. The U–REE mineralization superposed on the titanomagnetite deposits in the Chineysky pluton has not analogues in the world’s practice. The occurrences of uranium mineralization have been noted in form of pitchblende and U–Th rims around chalcopyrite grains at the Unkur copper deposit hosted in sedimentary rocks. The enrichment in U and Pb has been documented in crosscutting quartz veinlets with bornite mineralization at the Udokan deposit.

Mineralogical and Geochemical Characteristics of Lead-zinc Ore Deposits, and Potential Accompanying Components in the Cho Don - Cho Dien Area, Bac Kan Province, Vietnam

The Pb-Zn mineralization in the Cho Don - Cho Dien ore districts often occurs in 2 types: (1)oxidized ore near to the surface and (2) sulfide ore at deeper section. Based on microscopic observations,sulfide ores can be divided into sphalerite-galena-pyrite and/or galena-sphalerite mineralization types. Toexamine the geochemical features of the Pb-Zn ores, SEM-EDX and ICP-MS analytical methods wereperformed in this study. Previous δ34S data of Pb-Zn concentrates, and sulfide minerals from variousdeposits suggest that the Pb-Zn ore-forming fluids might be related to the felsic-granitic magmaticactivities rather than a genesis of stratiform type. Geochemical data show that the major, minor, and traceelement compositions of lead-zinc ores have wide ranges of variation even in each deposit. The sulfideores are generally higher in economic components than those in the oxidized ores. The positivecorrelations between Pb-Ag can be found in the entire dataset, whereas excellent Zn-Cd correlation canonly be observed from Cho Don ore samples. Apart from the principal components (Pb and Zn), the oresalso contain other accompanying elements that supply high-technological manufacturing industries. Ofwhich As, Cu, Ag, Sb, and Cd could be potential by-products and can be extracted during smelting Pb/Znconcentrate processes, and need more detailed studies for every deposit.

Industrial Heap Bioleaching of Copper Sulfide Ore Started with Only Water Irrigation

Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper sulfide ore that began with only water irrigation without the addition of sulfuric acid was successfully implemented and introduced in this manuscript. The mineral composition and their behavior related to the production and consumption of sulfuric acid during the bioleaching in heaps was analyzed. This indicated the possibility of self-generating of sulfuric acid in heaps without exogenous addition. After proving by batches of laboratory tests, industrial measures were implemented to promote the sulfide mineral oxidation in heaps throughout the acidifying stages, from a pH of 7.0 to 1.0, thus sulfuric acid and iron was produced especially by pyrite oxidation. After acidifying of the heaps, adapted microbial consortium was inoculated and established in a leaching system. The launch of the bioleaching heap and finally the production expansion were realized without the addition of sulfuric acid, showing great efficiency under low operation costs.

Application of a nanosecond corona discharge generator for electrical separation of ores

The use of a pulsed nanosecond voltage source in a corona separator was investigated. Measurements of the distribution of corona discharge current were obtained. The influence of the interelectrode distance on the distribution of the corona discharge current was investigated. Experiments with gold-bearing quartz-sulfide ore and ilmenite ore were carried out. A concentrate was obtained with a gold content of 48 g/t, a mass equal to 18.7% of the original, which corresponds to the extraction of 92% of gold. The titanium content of ilmenite was enriched from 2.87% to 18.1%.